Facial weakness

The facial nerve is composed of two parts: the motor fiber and the intermediate nerve that innervate the facial muscles. The intermediate nerve consists of sensory and parasympathetic fibers. Facial injuries can be found in the brainstem, skull base, facial nerve canal and its distal end. Because the abductor nucleus and pontine lateral vision center are adjacent to the facial nucleus. Therefore, brainstem lesions involving the facial nerve are often accompanied by cross paralysis consisting of eye abduction or lateral paralysis. Facial nerve injury is mainly manifested as facial paralysis or facial muscle spasm.